Tube cutter



s. N. ARNOLD 1,748,099

TUBE CUTTER Filed May 31, 1928 2 Sheets-Sheet mess" STNHELD N. ARNOLD. 5% WM5, SH01/mm2* I L7# E Feb. 25,' 1930.

Feb.v 25, 1930. s. N. ARNOLD 15748099 TUBE CUTTER Filed May 51. 1928 2 Sheets-Sheet v 2 wvcmoz STANHELD N. ARNOLD j UNI'IEDv STA v after being mounted.

Patented Feb. 25, 1930 Tas PATENT STANFIELD N. ARNOLD, oF NEW YORK, N. Y.

TUBE CUTTER Application mea May 31,

My invention relates to a tube cutter forl cutting tubes of boilers, condensers and similar apparatus either for removal and replacement, or for trimming the ends of the tubes Owing to the restrictions in and about the outside `of tubes and boilers and other heating appliances, if a tube is to be cut while in position in the apparatus, it cannot. be out from its outer surface, but must be cut from its interior. Heretofore, cutters for this purpose have been constructed with a number of cutting wheels, `usually three in number, which are advancedy in a, step vby step manner by means of a positive forcing mechanism. This construction required considerable space for .the cutting wheelsand, therefore, limited' the v use of such cutters to tubes of relatively large diameter. Moreover, the positive and definite i 20 radvancement of the cutting Wheels at intervals, put astrain on thewheelsv as they were forced intothe metal of the tube and', at times, J ytended to injure both the cutting wheels and the tube being cut. f l Y VThese disadvantages are obviated in my invention, among the objects ofwhich are to provide atube cutter capable of use in tubes of small diameter; to provide a tube cutter that 'imposes a continuous, uniform cutting pressure and a gradual, continuous advance of thecutter into the tube wall; to provide a cutter disc advancing mechanism that automatically advances the cutting edge as the -depth of the cut increases; to provide'a cutter y mechanism that enables a single advancing cutting disc to be used; and to provide'a cutter mechanism that may be inserted in tubes lnot in alignment with the driving-mechanism,

`and in which the cut-ting discor element may 40 be released and brought intocutting position after being placedin the tube to be cut.

Further o'bjectsand features of my inven- /tion yare to provide cutterv supporting rolls that .spread and widen the cut and thus'fa- L15 cilitate the action of the cutter edge to vprof, vide a single point supporting roller Contact; to provide a compact and effective spring mechanism for pressing a cutting roller into the tubeand for kreleasing the spring; and to .provide aneccentric cutteractuating means and set forth in the following specification 1928. Serial No. 281,697.

for advancing the cutting tool against the inner surface of the tube to be cut.

lVitli these and other objects in view, the invention comprises the tube cutter described and claims. n The various features of the invention are shown in the accompanying drawings, in which:

Fig. 1 is a longitudinal sectional view of a tube cutter embodying a preferred form of the invention, and showing the position of the cutter in a tube to* be cut.

Fig. 2 is a longitudinal sectional view of a modied form of tube cutter.

Fig. 3 is a perspective view of a modified construction for actuating a cutter advancing mechanism centered eccentrically of the axis of the cutter. l f

Fig. 4 'is a cross section of the tube cutter 70 taken on the line 2-2 of Fig. 2.r

Fig. 5 is a longitudinal section of a modified form of tube cutter adapted to be driven through a universal joint from a drive kout of alignment with -the axis of the cutter.

Fig. 6 is a cross sectional view, on an enlarged scale, of the tube cutter of Fig. 5 taken on line 6 6.

,Fig 7 is a longitudinal sectional view taken similarly to that of Fig. 5, of a modified .form of the'cutter for cutting tubes out of alignment with th e cutter driving mechanism.

In my present invention a cutting disc is mounted in a supporting head which may be placed at the desired position within the tube to be cut, and is rotated with the supporting head during the cutting of the tube. The cutting disc is so supported within the cutting head by a driving eccentric thatit `may be' pressed outwardly against the inner surface of the tube. ,A continuous cutting pressure is imparted to the cutting disc by means of a Vspring under'tension which causes the disc The carriage 14 is guided in a recess 15 of a cutter head 16 so that it may slide inwardly and outwardly in said recess. The inner end of the carriage 14 engages an eccentric 17 carried at one side by a smalltrunnion 18 journaled in the head 16 and, at the other side, by a larger trunnion 19 j ournaled in the inner end of a driving sleeve 20. To economize in space, the eccentric 17 is provided with a circumferential groove 21 which receives the edge portion or" the disc 10.

in the position shown in Fig. 1, the disc 10 and carriage 14 are drawn inwardly within the cutter head. 'As the trunnions 18 and 19 are rotated, the eccentric 17 carries the carriage 14 and disc 10 outwardly of the cutter headand into contact withthe 'inner surface 'of a tube 22 to be cut.

The continued rotation ot the trunnions 18 and 19causes the cutter 10 to enter more deeply into the tube 22 until a rotation of 180O has been reached, whereupon turtherrotation causes the cutter to be withdrawn into the cutter head.

In use, the cutter head is placed within the tube 22 vand so positioned that the cutter 10 is at the pointwhere the tube is to be cut. A torsional stress is then put upon the trunnion 19 by means of a helical spring 23, one end of which enters a groove or key-way 24 in the trunnion 19, and the other end o which Venters a corresponding groove or key-way 25 in a disc or collar 26 which may be rotated within the sleeve20 to wind up the spring 23 and place it under tension. The torsional stress thus placed on the trunnion19 causes it to rotate until the cutter 10 comes into contact with the inner surface oit the tube 22 vand rests against the tube-wall with a pressure determined by the tension of the spring 23. The

driving sleeve 2O is then rotated, causing the Ycutter head 16 to rotate and carry thecutter disc 10 in a circle about the inner surface of the tube 22. rlhe continuous rotation of the cutter disc 1() causes it to score and .penetrate the inner surface of the tube. Therotation of the cutter head and disc and the continuous outward pressure applied by the spring 23 on the disc, causes its penetration to increase until it completely severs-the tube.

v'To put the spring`23 under tension, the col- Alar 26 is keyed, by means of a pin 27, to and rotated by, a mandrel 28, one` end of which is ,'jourualed in a suitable recess in the trunnion 19, and the other end ot which projects through, and is journaled in, a ratchet head 29 mounted in the outer end of the sleeve 20.V

Longitudinal 'movement' of the ymandrel 28 vis prevented by means of a sleeve 30 which bears against the inner `end of the ratchet head 29. The outer, 'projecting end of the mandrel 28 is threaded into a turning head 31,

vthe inner portion of which is enclosed by a `ratchet handle 32 slidable on the turning head and on the mandrel 28. The ratchet handle 32 is slidable on the turning head 31, but is keyed mandrel. Y

rotation of the ratchet handle. Theinner end of the ratchet handle 32 is provided with a number of saw teeth projections 35, which en-V gage corresponding saw teeth depressions' 36 in the ratchet head 29. 'To maintain the teeth 35 and 36 in engagement, the ratchet handle 32 is normallyrurged towards the ratchet head 29 by means of a helical spring 37 within the recess 38 ofthe ratchet head 32, which en- Vcircles the mandrel 28 land presses, at one end, against the turning head 31 and',fat the Y lother end, against thefinturned end 39 of the recess 38.

After the cutter headg16 vand the supporting and driving sleeve 20'have been properly positioned for the cutto be made, the tensioning collar 26 is given therequired Vrotation relative to the `Vsleeve 20, by

drawing the ratchet handleV 32 outwardly against the pressure of the spring 37 until thefratchet teeth 35 and36 are disengaged,

and in then turning the ratchet head 32 with Va left hand or counter-clockwise movement relative to the ratchet head29, until the ro-Y tation of the mandrel 28 and collar 26 place 35 and 36l into engagement. The ratchet head 29 is prevented from turning when the ratchet handle 32l is drawnupwardly and' turned by means of handles,-n`otshown, that may be inserted into recesses 40 and 41 in the ratchet head. v

The sleeve 2O may be rotated bymeans of -a torsional stress applied to a squared end v42 of the turning head 31 or, the head may be turned by 'means of bars passed through transverse openings 43 and 44. VTo prevent turning and'V unthreading of vthe turning head 31 Jfrom the mandrel 28, a transverse locking pin 45 may be driven ythrough the threaded portions of the turninghead and The'cutting headk and driving collar 20 may be held in their positions in the tube 22v by means of a split ring 46 encircling the outer portion of thefsle'eve 20, and` adapted 7 to be slid to position against ahand-hole sheet! 47, andtightenedwinl position on the .Y

sleeve 2O by means of a thumbscrew 48.

rlhe reaction or bac-k thrust rolf the cut-' ting disc 10 on the cutter'head 16fis supported'on the wall ofthe tube 22 by means vot' a number of rollers 49 about afsh'aftsurface at the free yend of the cutter head.

The rollersy 49 are held in position'by'means of end pins 51 whichproject into an annu-V larv recessx52 on the *,head 16, and pins whichv project into asimilar annular recess 54 in an yend collar 55 which is threaded ontothe end of the cutter head.y 'Ihe shaft ysurface 50` may be concentric withv the axis of the cutter head so that the rollers 49 contact throughout the ent-ire surface of the tube but, inasmuch as the pressure is exerted only at the point diametrically opposite from the cutter 10, the shaft surface 50 is eccentric and is placed somewhat away from l the cutter disc 10, so ythat the rollers 49 contact with they inner wall of the tube only aty aV point diametrically oppositer from that of the cutter disc.

In the modification shown in Fig. 2, the

*cutter disc 10, carriage 14 and cutter head l16 are arranged in the same relation to the ydriving tube 20 as in the embodiment shown in Fig. 1. However, in these modifications,

,c the mandrel 28 does not extend to the trunniony 19 and, instead of the helical spring 23, a fiat laminated spring 56 is fastened or pinnedat one end to the journal 19 by means of a pin 57 and, by means of a pin 58 at its other end,is secured to a disc 59, which is also pinned tothe end-of the mandrel 28. The turning of the mandrel 28 relative to the collar 20, therefore, serves to put kthe .30

spring 56 under. torsional stress which transmits'v the required tortional stress to the journal 19 and causes the cutter 10 to `press'into the inner surface of thel tube 22.

- In these modifications, shown,v in Figs. 2 and 4, also' a diierentftype of'thrust rollers v60 and 61 are provided iand are mounted in obtuse angle sok that as they are pressed into the cut made by the cutter 10, they tend,

in VVthef'manner of a wedge, to spread ,the Vgroove thus formed andto widen it so that f itdo'es not have a tendency to'grip the side edgesgof they cutterv 10. vA more effective cutl tingactiongis thus obtained and there'is less f likelihood of breakage of the hard cutting "edge ofthe cutter.. iWhenthe ridge 62 has entered toits, maximum ldepth intothe cut kor groove, ythe cylindrical 'portions of the roller rest against the inner surface of the g means Aof screws 365.

ltube 1 and thus-receive'the thrustV and prevent/,an excessive wedging action. The

yrollers 60 and 61 are provided with end trunnions 63 which vare vmounted. in bearings in a suitablev 1recessi'n the lcutterfhead 16, and

are retained "inposition by meansofla strap 64 Asecured. at its'ends in the cutterhead by In the' above describedforms of invenytionfthe'trunnimis18 and 119 are centered :55j

on theaxis of the cutterjhead 16 and tube^20.

To 'enable a cutter head to be placed in a tube of very small diameter, it may be necessary,

in orderto mount a cutter disc of therequired size in such a small space, to center the trunnions 18 and 19 eccentrically from the axis of the cutter head and diametrically opposite the axis of the cutter wheel, as is shown in Fig. 3. In this construction, theend of the spring 23 is not secured directly to the trunnion 19, but is secured to a disc 66 freely rotatable in the tube 2O and connected to the trunnion 19 lby means of an Oldham coupling disc 67, having a key 68 on one face slidably engaging` a groove 69 in the adjacent face of the disc 66, and having a key 70 at right angles to the key68 on the opposite face of the disc and slidablyengaging a keyway 71 on the adjacent face of the trunnion 19. As th-e disc 66 is rotated, the disc 67 rotates and slides to positions that enable it to transmit its rotating movement to the trunnion 19. The pressure of the spring 23, or of the spring 56 in case a flat spring is used, is thus transmitted to the eccentric trunnions 18 and 19.

The form of the invention shown in Figs. 5 and 6 is adapted for the cutting of a tube to which access cannot be had through an opening in direct alignment with the axis of the tube. It is also adapted for the cutting of tubes in which there is not much space between the linepon which the tube is to be cut and an adjacent hand-hole having an opening out of alignment with the axis of the tube. Inthis form of the cutter, the arrangement; of the cutter disc 10, cutter carriage 14 and eccentric 17 in the cutter head 16 is subdisengaged from the trunnion 19 when tight- 1 eninff the spr1ngand re-engaged by suitable clutch mechanism tofy drive the eccentric and the carriage cutter to cutting position. The collar 73 is held from longitudinal displacement by means of an inner 'sleeve 74 span-v ning the distance between the adjacent facesv of the collar 73 and end plate 72, and held spaced from the mandrel'28 by shoulders 75 and 76, respectively, on the collar 73 and 'end plate 72. The inner sleeve 74 also prevents the inward buckling of the spring 23 against the mandrel 28.

The collar 73, when disengaged from the trunnion 19, may be rotated to tighten the spring 23 by means of the mandrel 28 which is splined by a key 77 directly to the collar"r- 73. The mandrel 2.8 is, however, slid'able longitudinally of the collar 73 and is envlarged at its inner end to form a` clutch plate 78, which slides Within a recess 79 iii the collar 73. Theciutch plate 78 is urged towards the end of the trunnion 19 by means of a helical spring 8() confined between the tace ot the clutch plate 78 and a shoulder 81 projecting inwardly from the collar 73. The adjacent Vend of the trunnion 19 is provided with 'a y through a transverse opening 83, or by other means, in a direction to cause the teeth of the clutch plate 78 to ride overthe teeth 82, compressing the sprino' 80. `Whcn the proper relative rotation between the cutter head 16 and the mandrel 28 has been attained, and the mandrel isA released, the spring 8O will immediately urge the clutchplate 7 8 into engagement with the teeth 82.

In this form of the device it is, oit' course, impracticable to Wind the spring 23 aliter the cutter has been placedV in its intended posi tion in the tube to be cut. ln Winding the spring 23, the trunnion 19 and eccentric 17 are held from movement relative to the cutter head 16. To this end, instead of the small trunnion 18 of Fig. 1, the end of the eccentric 17, opposite the trunnion 19, is provided With an enlarged trunnion 84 journaled in the cutter head 16, and having a cylindrical shoulder portion 8,5 of decreased diameter. The shoulder 85 is provided with a notch 86 which may be engaged by a dog 87 pivoted by a pin 88, in Va recess 89, in the cutter head 16. The dog 87 is normally urged by means of a spring 90 to cause it to engage the notch 86, and thus` hold the trunnion 84, eccentric 17 and trunnion 19 from rotating relative to the cutter head 16 While the mandrel 28 is rotating. When theproper tension has been placed ontlie rspring 23, the sleeve 2O and cutter head 16 are inserted, sleeve oremost, into the tube to lbe cut. The position of the sleeve 20 and cutter head 16 is gauged by means of a loose ring 91 clamped by means of a set screw 92 at the desired position o n the cutter head 16, so that it Vwill rest at the edge of the tube When the cutter 10 is at its proper position. The eccentric 17 is then released by pressingvth'e dogu 87 againstthe tension of the spring 90, to release the notch 86, whereupon the eccentric is rotated until the cutter 10 contacts With the inner surface of the tube and is held against the tube by the tension of the spring 23.

The cutters 10 and the cutter head 16 are 'rotated from a driving universal head 93 driving y'pin 921 eXten'ding throughfa latfor longitudinally widened slotvin the head 95, which is connected integrally With the sho-ul@ der by means of a short neck 96.V /As the j4 heads y93 and` 95 rotate, the rotational -move. ment is transmitted to the trunnions 84 and' 19, causing the eccentric 17 to rotate. VThe spring 23 and the reactionof the cutter V10y on the inner surfacev ofthe tube, however,VV holds the cutter 10 and cutter head`16 in: the

same relation asvvould be' the Vcase if the cutj Yter head 16 were driven.

In the event that it should befdesired to I'e- Y lease the tension 'of the spring'23. This can befdone by disengagingthe clutch plate 78 from the clutch teeth 82. To yenable this to 'be done when the exposed end vothe mandrel 28 cannot Abe reached from the outside end of a tube,:a pushrodl 971s mounted axiallyV in an axial recess extending from the neck 96 through the shoulder 85,v trunnion 83, eccentric'17 and trunnioh 19 to the clutch plate78. A transverse opening V98 in the neck 96 gives access to the fend of the push rod 97 andenables it to be displaced longitudinally against the clutch plate 78 and the action of the spring 80, until the clutch; plate 78 Yis disengaged from the Aclutch teeth 82, and the collar 73 and mandrel 28 may freely rotate until the tension ofthe spring 23is released.y

' This form o'tcutter may be adapted for use as a straight ordirectly driven cutter, in the same mannerv as in kthe modification shovvn in Figs. 1, 2 and 3. lnthis case, the driving head 93 and pin 9.a are removed and the plate 72 is replaced by a plate secured to the sleeve 2O and permitting an extension of thesleeve 20 to be threaded to the internally threaded the transverse opening 83, this'extension of n the mandrelbeing suitably journaled'in the extension oit vthe sleeve r2O. The cuttermay then be driven either' through theextension of the mandrel or the extension of the sleeve l20, in thesame manner fas in the case of the n Y modification shown in Figs. 1,2 and .Ass rthus adapted, the clutch .32, shown fin Fig. l,

maybe omitted, yas Athe same function is ac-VV Y complished by the clutch plate 78.

in u1@ modification Shown in rig. 7., uit f cutter may be driven through a' universal a rotatable'disc 99 at the outside end of the izlom sleeve 20, and secured iniplace by'a collar100 threaded into the endfof ythe sleeve 20. In'

tightening the spring 23 in this form of the device, the rotatable disc 99, is rotated from i almendra es to which a is directly Splined;

The mandrel 28y is rotated relatively to the sleeve 20, by meansv of a clutch plate 101 which is slidably splined to .the mandrel 28 and is provided with saw-shaped teeth 102 which engage complementary teeth 103 on the fixed collar 100.A The clutch plate 101 is urged towards engagement with the collar izo.

100, by means of a spring 104 within a recess 105 in the clutch plate 101, and confined between an internal shoulder in the clutch plate and a collet 106 fastened to the projecting end of the mandrel 28. The spring 23 may, therefore, be tightened by rotating the clutch plate 101, which thereupon slides out of engagement with the collar 100 until the proper tension is reached. whereupon by releasing head 93 is removed and the mandrel 28 is r eplaced with one of the required length, as in i Fig. 1. The sleeve 20 is replaced with a longer sleeve, to the outer end of which the collar 100 and the clutch plate 101 maybe secured or, the mandrel and sleeve may be replaced with one of the form shown in Fig. 1.

My invention, therefore, provides a tubev cutter which can be used in tubes of 'small diameter and in narrow, obstructed positions.

Through my invention, also, a continuous,y

steady pressureis automatically applied to the cut-terdisc, requiring no attention on the part of the operator and obviating all risk that the cutter disc may be forced too rapidly, or spasmodically, into the tube being cut.

As changes of construction could be made within the scope of my invention, it is intended that all matter contained in the above description `or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

' Having now described my invention, what y spreading ridges in a common plane with said disc, and means for moving said cutter disc awayfroni the axis of said head.

2. A tube cutter which comprises a cutter head to be positioned within a tube cutter, an eccentric in said cutter head, a cutter disc carriage engaging said eccentric and guided inwardly and outwardly 1n said cutter head, a cutter disc carried .in said cutter disc carriage, a driving sleeve mounted on said cutter head, a spring within said sleeve connected to said eccentric,and a ratchet for rotating and holding the free end of said spring in said sleeve. n 3. A tubecutter which comprises acutter head to be positioned within a tube to be cut, an eccentric in said cutter head, said eccentric being journaled eccentrically oi: said cutter head, a cutter disc carriage engaging said eccentric and guided inwardly and outwardly in said cutter head, a cutter disc carried on said cutter disc carriage, a driving sleeve for said cutter head, a spring within said sleeve, means for connecting'one end of said spring to said eccentric, and means for rotating and holding the other end of said spring in said sleeve.

4. A tube cutter which comprises a cutter head to be placed withina tube to be cut, means for rotatably supporting said head in the tubewalls, a driving sleeve connected to said cutter head, an eccentric mounted in said cutter head, a cutter carriage slidably mounted inV said cutter head and engaging saideccentric, a cutter disc on said carriage, a spring Vconnected'at one end to said eccentric, a mandrel connected to the opposite end of said spring, a clutch face onsaid sleeve, a clutch slidably mounted on said mandrel, andv a spring urging said clutch to said clutch face. 5. A tube cutter which comprises a. cutter y'head to be placed-within a tube to be cnt,

spreading rollers for. supporting said head in said tube walls, a driving sleeve connected to said cutter head, an eccentric mounted in said cutter head, a cutter carriage slidably mounted in said cutter head and engaging said eccentric, a cutter disc on said carriage, spreading ridges on said supporting rolls in the 'plane of said cutter disc, a spring connectedat one end to said eccentric, a mandrel connected tothe opposite end of said spring, a clutch face on said sleeve, a clutch slidably mounted on said mandrel, and a spring urging said clutch to said clutch face.y f

6.. A tube cutterwhich comprises a cutter head to be placed within a tube to be cut, means for rotatably supporting said head in the tube walls, a driving sleeve connected to said cutter head, an eccentric mounted in said cutter head, a cutter carriage slidably mounted in said cutter head and engaging said eccentric, a cutter disc on said carriage, a mandrel extending through said sleeve, a spring connected' at one end to said mandrel, a clutch between said eccentric and said spring, and means for rotating said clutch relative to said eccentric.

7. A tube cutter which comprises a cutter hea-d to be placed within a tube to be out, an eccentric mounted in said cutter head, a cutter carriage slidably mounted in said cutter head and engaging said eccentric, a cutter disc on said carriage, a spring conlined between said cutter head and said eccentric,

and ymeans for releasing said ,springn connection between said head and said eccentric. 8. A tube cutter whichcomprises va cutter head to beplaced within a tubejtofbe cut, an eccentric mounted in said cutter head, acutter carriageslidablymounted in said cutter head and engaging said eccentric, a cutter disc on said carriage, a spring confined between said cutter head yand `said eccentric, Aand ree leasable means for preventingrotation of said eccentric in said cutter head. f Y

r9. A tube cutter which comprises a cutter head to be placed withina tube to be cut,an eccentric mounted in said cutter head, a. cutter carriage slidably mounted in fsaid cutter head and engaging said eccentric, a cutter disc `on said carriage, a spring confined between said cutter head and. said eccentric, re- Y leasablemeans for preventing the rotation of said eccentric'in said cutter head, and anniversal joint connected Vdirectly to .said eccentric. Y f 1 f` o 10. A tube cutterwhich'comprisesa cutter head to be placed within a tube to be cut, an eccentric mounted in said'cutter head, a'cutter carriage slidably mountedin said cutter lhead and engaging said' eccentric, a cutter disc on said carriage, a spring connected to said cut- ,ter headV and stressed torsionallfv to said 'eccentric, driving means connected directly :to said eccentric, a vnotch in the'journals of said eccentric, and a spring-pressed retainingdog 0n said cut-ter yhead engaging said notch.

ll. A tube cutter which comprises va cutterl'r head to be positioned within a tube to be cut, an eccentric in said cutter head, alcutter disc carriage engaging said eccentric and guided inwardly and outwardly in said cutter head, a cutter disc mounted on said cutter disc carriage, .afdriving sleeve for said cutter head, a leaf spring within said sleeve connectedV at onefend to said eccentric, andmeans Vfor rotating and holding the' other end-of said g spring in said sleeve.

In testimony whereof I atiix myfsignature.

STANFIELD N. ARNOLD. 

